Automobile door latch mechanism



Feb. 17, 1948. w. J. TIERNEY ETAL 2,435,987

AUTOMOBILE DOOR LATCH MECHANISM Filed Sept. 1, 1944 I 3 4 2 m g m 9 4- I30 447 36 Z Java/21 0?? I WL'ZZiwwJfic-Wzey gefi zj. pr'mon/ v f i 25 73 Patented Feb. 17, 1948 AUTOMOBILE DOOR LATCH MECHANISM William J. Tierney, Cletus Ii. Harmon, and Fred asaianon W. A. Villem ure, Rockford, Ill.,

The Atwood Vacuum Machine Company. Bockford, 111., a copartnership composed of Seth B. Atwood and James T. Atwood Appllcation'September 1, 1944, Serial No. 552,250

22 Claims.

This invention relates to a new and improved automobile door latch mechanism.

In the later designs of automobile doors, the trend has been to widen the glass, thereby reducing the space next to the glass run within which the door latch mechanism can be installed. The square shaft turned by the handle is accordingly crowded over close to the edge of the door, and the same is true of the shaft connected with the door lock. The rotary type latch bolt disclosed in the Van Voorhees Patent 2,143,965, and others, arranged to operate in a substantially vertical plane between the edge of the door and the pillar, is particularly well adapted to these conditions, whereas a horizontally reciprocated bolt of the conventional type is not suitable. The rotary type bolt provides ample travel in looking and unlocking without interference with the adjacent channel for the glass run andoffers the further advantage that the opening up of the joint between the door and pillar, due to body distortion, does not affect the operation of this type of latch, whereas it presents serious difliculties with the reciprocable type bolt. It is, therefore, the principal object of our invention to provide a door latch mechanism incorporating the rotary type latch bolt, the actuating and locking mechanism cooperating therewith being all compactly arranged in a plane in transverse relation to the bolt alongside the inner wall of the door, and designed for operation by the door handle and door lock shafts extending substantially in right angle relation thereto and alongside the adjacent edge portion of the door.

The present door latch mechanism has been further designed so as to permit locking either door from the inside and to prevent locking out of the driver when the door is slammed, in the event the inside locking means has been operated to locked position.

A further feature of the present door latch mechanism is the provision of a spring pressed over-center snap action member cooperating with a rotary dog in such a way that the door may be locked from the outside or inside and the audible click of the over-center member, when thrown over center, serves to indicate to the driver deflnitely that the door has been locked, so that it is not necessary to try turning the handle to make certain of it. The remote control link, operable by the usual inside handle, is operatively connected to the rotary dog and is therefore movable to retracted position with the dog when the door is unlocked from the outside with a key, thus 2 structions, which permitted unlocking of the car with a key only from the same side where the key was used inlocking the car.

The invention is illustrated in the accompanying drawing, in which- Fig. 1 is a horizontal section through the free edge portion of an automobile door and the adjacent pillar, showing the dovetail portion in which the latch bolt is provided, and also the arrangement of the door latch mechanism of our invention in relation to the latch and the adjacent channel for the glass run:

Fig. 2 is a vertical cross section on the broken line 2-2 of Fig. l, and including the inside remote control;

Fig. 3 is a vertical section in a transverse plane on the broken line 3-4 of Fig. 2, and

Fig. 4 is a vertical sectional detail through the dovetail in the plane of the line 4-4 of Fig. 2, showing the striker on the door pillar.

The same reference numerals are applied to corresponding parts throughout the views.

Referring first to Fig. 4, the reference numeral 5 designates the spring pressed rotary latch bolt pivotally mounted, as at 6, on a horizontal axis for swinging movement in a vertical plane between the edge of the door I (Fig. 1) and the pillar 8. The stud providing the pivot 6 has upset ends serving to secure the dovetail shaped housing 9 to the back plate It. The housing 9 is also suitably secured to the plate III by its flange portion II and the two parts thus secured together are adapted to be riveted or otherwise suitably secured to the edge wall of the door I. The dovetail shaped housing 9 projects through an opening in the edge wall of the door and is arranged to have wedging engagement between a striker plate i2 and a bumper I; carried on a mounting plate It suitably secured to the door pillar 8. The striker plate I! is rigidly secured to the mounting plate H by rivets I5 and has two teeth It and ii for cooperating with the tooth it of the latch bolt 5, that projects through an opening i9 provided in the bottom wall of the dovetail shaped housing 9. When the door is closed properly, the tooth i8 is engaged under spring pressure behind the tooth IS, the tooth l1 being merely a safety catch as is well known in this art. The bumper it consists of a sheet metal wedge shaped housing 20 fastened to the mounting plate It with freedom for limited up and down, as well as in and out, movement parallel to said plate under the restraint of a rubber block with which the housing is filled, the rubber block avoiding a common objection to other earlier con- 68 having a tight lit in the housing and around the fastening stud for this purpose. It is--obvious,-

therefore, that when the door is closed the dovetail shaped housing 9 entering between the striker plate i2 and bumper i3. in the manner of the conventional dovetails of automobile doors, will accurately locate the latch bolt 5 with reference to the striker plate I2 and, therefore, insure positive latching of the door. The wedging action obtained, particularly with the yielding of the rubber block in the bumper i3, eliminates likelihood of the door rattling when the car is in motion, and also insures keeping the tooth t8 properly engaged behind the tooth [6 at all times. It should also be clear that regardless of the usual amount of distortion and consequent opening of the gap between the door and pillar, the tooth i8 always maintains the same length of engagement in a vertical direction with the tooth l5 sov that there is no danger of accidental opening of the door, as there is with the reciprocable type bolt where the amount of engagement between the bolt and its striker varies according to the size of the gap between the door and pillar, and the fact that the latching is done directly in the dovetailed portions on the door and pillar obviously insures uniformly better results than would be obtainable otherwise. The latch bolt 5 is urged toward engagement with the striker plate by means of a spiral spring 2|, the inner end of which is carried on a stud 22 rigid with the dovetail shaped housing 9, the active outer end of the spring bearing on top of the outer end of the latch bolt, as clearly appears in Fig. 4. This much of the present structure is disclosed in the Van Voorhees Patent 2,329,232 and no invention is, therefore, claimed in these details, excepting insofar as they form a part of the novel structure of our invention.

A roller 23, which is preferably of hardened steel or fiber, but may be a rubber covered metal roller, and is rotatable freely on the shouldered portion of the rivet IS in the cut-out side portion 24 of the striker plate I2 so that a portion thereof projects sufficiently from the outer end of the striker plate roper, as indicated at 25, to insure first engagement with the noseof the latch bolt in the closing of the door, serves to reduce wear by the rolling action obtained and distribute the little wear over the circumference of the roller and accordingly insure much longer life. The rolling action also makes for quietness and smoother and easier operation all around. A rubber bumper 26 projects from a hole 21 provided therefor in the striker between the teeth i6 and i1 and tends to further silence the door closing operation. Being located between the teeth, the bumper 26 prevents a metal-to-metal clicking sound as the bolt 5 is run home and the bumper is not subjected to much wear in this kind of operation and accordingly lasts substantially as long as any other part. The only time this bumper would be subjected to any continuous engagement by the bolt would be for such short intervals when the driver fails to slam the door and the latch bolt 5 takes hold of only the safety catch tooth i1, and, of course, such occurrences are not frequent. If desired, another bumper similar to bumper 26 may be provided in the latch bolt 5 directly behind the tooth i8, as indicated at 21, to engage the end of the tooth I5 when the latch bolt 5 falls home, whereby to further silence the door closing operation.

The back plate Iii-mentioned above is bent nearly at right angles, as indicated at 28, to provide a portion 29 in fixed relation to the dovetail l 4 I shaped housing on which the actuating and locking mechanism now to be described is mounted. The latch 5 has a pin projection 30 on the outer end thereof which projects laterally through an opening 3i provided in the back plate ii) for operation by a lug 32 on the rotary dog or roll-back33 that is pivoted, as indicated at 34, on the back plate portion 23. The dog 33 has another lug 35 which is engaged by 8. lug 35 on a slide 31 that is slidable vertically with respect to the dog 33 and its pivot stud 34 within the limits of the elongated slot 38 provided in said slide. A lateral projection 39 on the lug 35 is movable in an arcuate slot 40 in the back plate portion 29 and has the active end 4i of a spiral spring 42 engaging the same and tending normally to return the dog 33 to the retracted position shown in Fig. 2. The other end of the spring 42 is fixed to the back plate portion 23 as at 43. A cam 44, which has a hub portion 45 rotatable in a bearing 45 provided therefor in a cover plate 41 suitably fixed to the back plate portion 29, as indicated at 41', slidably engages a lug 48 formed on the end of the slide 31 to communicate reciprocatory movement to the slide when the handle 50 of the door is turned. The latter has a square shaft 5| extending therefrom and entered in a square hole 52 provided in the hub portion 45 of the cam 44. It should be clear, therefore, that when the door is closed the latch 5 can be released by rotary movement of the dog 33, which movement is produced by reciprocatory movement of the slide 31, which in turn is produced by oscillatory or rotary movement of the cam 44 turning with the handle 50. The spring 42 resists this movement and accordingly restores the parts to their normal positions after such an operation. In Fig. 2 there is indicated a dotted position of the pin projection 30 which is the released position, the full line position being the normal or locked position of the latch bolt. The slide 31 is guided in its reciprocatory movement at one end by the pivot stud 34 working in the slot 38, and at the other end is guided between a lug 49 struck at right angles from the back plate portion 29 and the flanged end portion 49' of the cover plate 41.

The latch bolt can also be retracted by reciprocatory movement of the remote control link 53, the outer end of which has an elongated slot 54 provided therein for, detachably pivotally connecting the link to the stud 55 projecting from a third lug 56 provided on the dog 33. The link 53 is operable at its other end by a lever 51, having a hub portion 58 rotatable in a bracket 59 suitably secured to the door. The hub 58 has a square stem 60 projecting therefrom for connection to the inside handle (not shown). A leaf spring 6| suitably fixed at one end to the bracket 59 and slidable at its free end on the periphery of the pivoted end of the lever 51, engages normally in a notch 52 to hold the lever 51 and the inside handle with it in a predetermined neutral position. Now, of course, when the inside handle is turned in a clockwise direction to release the latch bolt and open the door, the spring 42 will serve to return the parts to normal position in the same way as when the door is opened from the outside. On the other hand, when the inside handle is turned in a counter-clockwise direction, a cam portion 53 on the lever 51 deflects the spring 6| enough to insure prompt return of the lever 51 to the neutral position as soon as the inside handle is released. This is highly important, because it means that the lock is "unloaded to the extent that if a key is used, as

from the outside after it has been locked by the remote control from the inside, the key need move only a few small parts of the lock mechanism and not the remote control mechanism too. Furthermore, in the slamming of the door this feature is important, because of the small inertia factor involved in the kicking of the dog 66 alone out of the way as compared with the much greater mass of the remote control link 63 and the operating lever 61 and other parts connected thereto. Counter-clockwise movement of the inside handle produces free movement of the link 63 to the left without any resultant rotary movement of the dog 33, because of the slot 66 which provides a lost motion operating connection between the link 33 and the dog 33 for this purpose. A cam shaped tooth 66 on the slotted free end of the link 63 in this movement of the link, strikes a ing 66 projecting from a rotary locking dog 66 pivotally mounted on the same stud 34 with the dog 33 and turns the dog 66 to a position in which a prong 61 on the dog 66 is disposed in blocking relation to 9. lug 68 struck at right angles from the slide 31, whereby to look the door from the inside. Under these conditions it should be obvious that the door cannot be opened from the outside be-' cause the slide 31 is blocked by the prong 61. Movement of the inside handle in the counterclockwise to lock the door from the inside is preferably limited by the engagement of a projection 63 thereon with a portion 16 of the cover plate II that is fastened to the bracket 53 and forms a part of the mounting for the lever 61. There is, therefore, no possibility of the link 53 transmitting any counter-clockwise movement to the dog 33, because the movement is limited at 69-16 within the range of lost motion afforded by the slot 56. If the driver has inadvertently operated the inside handle to door locking position when the door is open, there is no danger of his locking himself out by slamming the door, because under those conditions the lug 66, which in its locking position is disposed over the pin projection 36, as indicated in dotted lines in Fig. 2, is directly in the path of upward movement of the pin projection produced in the slamming of the door as the toothed end i6 of the latch bolt 3 rides up over the striker i'2. The locking dog 66 is accordingly kicked back to retracted position automatically under such conditions.

A spring pressed over-center lever 69' is oscillatably mounted on the lower portion of the plate 29 on a stud 16' and has its forked upper end Ii meshed with a downwardly projecting prong 12 provided on the locking dog 66 to hold the dog releasably in either its operative or inoperative retracted position. A coiled spring I3 having one end ll anchored to the plate 26 and the other end 15 anchored to the lever 63', serves to hold the lever 69' releasably in either of two extreme positions on opposite sides of a deadcenter and is subjected to sumcient distortion in center position at which the pivot 16 will come into alignment with pivots l6 and I6, and then it will require only a little further movement for the snap action to occur, the dog 66 being thrown forcibly to locked position under action of the spring 13. The driver hears the clicking sound in the snap action of the lever 63' and knows, therefore, that the door is definitely locked. The same snap action is utilized for the same kind of indication or signal in locking the door from the outside, as will now be described.

A cover plate 16 extends over the lever 69' and dogs 33 and 66 and is anchored to the plate 23 at its lower end, as indicated at 11, and is also rigidly secured in place by the riveting of the ends of the pivot studs 34 and 16'. A notch 13 is provided in the middle portion of one side of the lever 63' and receives the tapered prong of a locking cam 16, the hub portion 30 of which is mounted in a bearing opening M in the cover plate 16 and has a square center holeto receive the square shaft 32' adapted to be turned with a key from the outside of the door when the proper key is entered in the door look (not shown). In looking the door from the outside, the shaft 62 is turned in a counterclockwise direction and the cam I9, working in the notch 13, turns the lever 66' in a clockwise direction. As soon as the lever 66' has been turned slightly past the dead-center position, as previously described, it moves with snap action to the opposite extreme position from that shown in Fig. 2 and, of course, the driver hearing the clicking sound knows definitelythat the door is locked and he does not have to bother trying to turn the handle 56 to make certain of it. It will be remembered that the link 53 is automatically returned to neutral position when the door is locked from the inside by operation of the inside handle. That is of particular advantage when the door is unlocked from the outside with a key under such conditions, because it eliminates the drag that would otherwise be imposed if the link 53 and inside door handle had to be moved with the locking dog 66; the key, with the present arrangement, operates only the dog 66 through the medium of the lever 63', and, of course, these parts are operable easily, there being only the resistance of the spring 13 to overcome and the light friction on the pivots 16' and 34.

The door lock is preferably so constructed that the cam 13 will always be left in the middle or neutral position, shown in Fig. 2, when the key is removed from the lock. The notch 13 is wide enough to permit such return movement independently ofthe lever 69'. This is important, because it enables one to unlock the door by means of the inside handle operated lever 61 when it has been locked with the key from the outside, and vice versa. This feature of having the rotary dog 66 operable to retracted position by a key from outside the car when the door has been locked from the inside with the remote control is important because it enables the motorist to lock the right hand door with the key and the left hand door from inside with the remote control, and afterward to unlock either door with the key. With other constructions, a door locked from the inside with the remote control cannot be unlocked with a key from outside. Thus, when the motorist finds another car parked too close to his car for convenient entry on the right side, he can unlock and enter on the left side, and vice versa.

In conclusion. attention isicalled to the dotted 7 line showing of the channel 83 for the window pane 84 in Fig. 2, which emphasizes the fact that the shaft turned by the door handle 58 and the shaft 82 arranged to be turned with the key of the door lock are located close to the edge of the door in the confined space between the ed e of the door and the channel 83, whereas the dog 33 constituting the roll-back member and the locking dog 36 are disposed for pivotal movement about the pivot 34 farther removed from the edge of the door. In other words, the limited space next to the channel 83 does not place any limitation upon the design and construction of that portion of the present door latch mechanism cooperating with the pin projection 30 on the latch bolt 5, the dogs 33 and 86 being designed to accommodate the throw of the pin 30, independently of the limited space available between the channel 83 and the edge of the door. This is, of

course, by virtue of the fact that the dogs 33 and 88 are located adjacent the inner face of the door and the dog 33 is operated from the shaft 5| through the. intermediate slide 31 and the dog 88 is operated from the shaft 82 through the intermediate lever 69.

It is believed the foregoing description conveys a good understanding of the objects and advantages of our invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

We claim:

1. Latch mechanism for a door of a vehicle body, said door being mounted for swinging movement to and from closed position and adapted to have movably mounted therein a window pane with a portion of the path of movement of one of its edges in close proximity to a portion of the free vertical edge wall of the door, said mechanism comprising a spring-tensioned latch bolt element mounted for swinging movement in a plane parallel to said free vertical edge wall of the door toward and away from latching position. an outside operated handle arranged to turn a shaft extending substantially horizontally between the free vertical edge wall of the door and the window pane, a rotary roll-back disposed adjacent the inner face of the door substantially parallel to the window pane rotatable about a horizontal axis farther removed from the free vertical edge wall of the door than said handle shaft and operatively associated with said bolt element, a slide reciprocable in a plane parallel with said roll-back and operatively associated with the latter to retract said latch bolt element when said slide is reciprocated, means for translating rotary movement of the handle shaft to reciprocatory movement of said slide, a rotary locking dog turning about the same axis as said roll-back and arranged to block movement of said slide when turned to a locked position, said locking dog having a projection which is disposed in the path of retracting movement of the latch bolt element when said locking dog is in locked position, whereby said latch bolt element moves said dog out of blocking position when the door is slammed, and inside operated retracting means operatively associated with said roll-back and locking dog so as to set said locking dog in blocking position when moved in one direction and retract said latch bolt element when moved in the opposite direction.

2. Latch mechanism for a door of a vehicle body, said door being mounted for swinging movement to and from closed position and adapted to have movably mounted therein a window pane with a portion of the path of movement of one of its edges in close proximity to a portion 'of the free vertical edge wall of the door.

said mechanism comprising a 'spring-tensioned latch bolt element mounted for swinging movement in a plane parallel to said free-vertical edge wall of the door toward and away from latching posit-ion, an outside operated handle arranged to turn a shaft extending substantially horizontally between the free vertical edge wall of the door and the window pane. a rotary roll-back disposed adjacent the inner face of the door substantially parallel to the window pane rotatable about a horizontal axis farther removed from the free vertical edgewall of the door than said handle shaft and operatively associated with said bolt element, a slide guided for reciprocatory movement adjacent the inner face of the door and operatively associated with said shaft and roll-back to transmit rotary movement to the roll-back upon rotary movement of said shaft, a

locking dog rotatable about the same center as said roll-back and arranged when actuated to locking position to block the movement of said slide, locking means operable from the outside of the door and adapted to actuate the locking dog and including a shaft substantially parallel to the first mentioned shaft extending horizontally in the space betweenthe free vertical edge wall of the door and the window pane and adapted to be turned with the key of said locking means, and a spring actuated snap-over lever rotatable about a horizontal axis farther removed from the free vertical edge wall of the door than the shaft of said locking means and operable by said locking means from one extreme position to another and operatively connected with said locking 'dog.

3. A door latch mechanism comprising a vertically oscillatable latching element spring-pressed to move in one direction, a spring-tensioned rollback operatively-associated with lateral projection on said latching element fordirect engagement thereon, a support on which said roll-back is pivotally mounted, a reciprocable slide guided on said support and having a projection arranged to engage a projection on said roll-back to turn the same against its spring action to retract the latching element, a locking dog oscillatable on the roll-back pivot to a position blocking retracting movement of said slide, said dog having aprojection which in the blocking position of the dog is disposed in the path of movement of the projection on the latching element, whereby said dog will be automatically kicked back to an outof-the-way position if disposed in blocking'position when the door is slammed, outside operated retracting means operatively associated with said slide to move the same in one direction, said slide being returnable under spring action of the rollback, said roll-back having an extension, a reciprocable link member having a pin and slot connection with said extension, and a camshaped extension on said link arranged in a forward movement of the link on its lost motion to slidably engage the projection on the locking dog to move said dog to blocking position, said link in a rearward movement being arranged to turn said roll-back against its spring action to retract said latching element."

4. A door latch mechanism comprising a vertically oscillatable latching element springpressed to move, in one direction, a springtensioned roll-back operatively associated with a lateral projection on said latching element for direct engagement thereon, a support on which roll-back to turn the same against its spring.

action to retract the latching-element, a locking dog oscillatable on the roll-back pivot-to a position blocking retracting movement of said slide,

outside, operatedretracting means operatively associatedwith said slide to move the same in one direction,

ing an extension, a reciprocable link member having a pin-and slot connection on said extension, and a cam-shaped extension on said link arranged in a forward movement of the link on its lostmotion to slidably engage a projection on; said dog to move said dog to blocking position,

said link in a rearward movement being arranged said slide being returnable under spring action of the roll-back, said roll-back hav- 10 about a horizontal axis and operable by said locking means from one extreme position to another and operatively connected with said locking dog. l,

10. A door latch mechanism comprising a var.- tically oscillatabie latching element sprin pressedto move in one direction. a spring-tensioned roll-back operatively associated with a lateral projection on said latching element for direct engagementthereon, a support on which said roll-back is pivotally mounted. a reciprocabie slide guided on said support and having a projection arranged to engage a, projection on said roll-back to turn the same against its spring action to retract the latching element. a locking dog oscillatable on the roll-back pivot to a Dosition blocking retracting movement of said-slide,

to turn said roll-back against its spring action to I retract said latching element.

5. In a latch mechanism for a door of avehicle body, the combination of a latch bolt, a roll-back therefor, an outside operated retracting means 'operatively associated with said roll-back, a lock- -ing dog movable to a position blocking said out- 'has been moved to blocking position by the ina side operated retracting means.

.6. A door latch mechanism as set forth in claim 5, wherein the inside operated retracting means includes a link having a lost motion operating connection with the roll-back and'having a camshaped portion thereon for engagement with the projection on the locking dog to move the same to blocking position.

7. A door latch mechanism as set forth in claim 5. wherein the key-operated locking means in-' outside operated retracting means operativeiy associated with said slide to move the same in one direction, said slide being returnable under spring action of the roll-back. said roll-back having an extension, a reciprocable link member having a pin and slot connection with said extension, a

cam-shaped extension on saidlink arranged in 1 arranged to turn said roll-back against its spring cludes a spring-actuated snap-over control lever operatively connected with said locking dog and arranged to snap over a dead-center when moved from one extreme position to the other, the keyoperated locking means including an element rotatable with the key and having a lost motion operating connection with said snap-over control lever. 1

j 8. Latch mechanism for a door of a vehicle body as set forth in claim 2, wherein said looking dog has a projection which is disposed in the path of retracting movement of. the latch bolt element when said locking dog is in locked position, whereby said latch bolt element moves said dog out of blocking position when the door is slammed, the mechanism including inside operated retracting means operatively associated with said roll-back and locking dog so as to set said locking dog in blocking position when moved in one direction and retract said latch bolt element when moved in the opposite direction.

9. A door latch mechanism as set forth in claim 3, including locking means operable from the outside. of the door and adapted to actuate the locking dog and including a shaft adapted to be turned with the key of said locking means, and a spring actuated snap-over lever rotatable action to retract said latching element. locking means operable from the outside of the door and adapted to actuate the locking dog and including a shaft adapted to be turned with the key or said locking means, and a spring actuated snap-over lever rotatable about a horizontal axis and operable by said locking means from one extreme position to another and .operatively connected with said locking dog.

11. In a latch mechanism for a door of a'v hicle body, the combination of a latch bolt, a roll-back therefor. an outside operated retracting means operatively associated with said rollback, a locking dog movable to' a position blocking said outside retracting means, an inside operated retracting means operatively connected with said roll-back. said locking dog having a projection operable by said inside operated retracting means for movement of the locking dog to blocking position, and locking means operaable with a key from the outside of the door to move said locking dog to retracted position after it has been moved to blockin position by the inside operated retracting means. 1

12. A door latch mechanism as set forth in claim 11, wherein the key-operated locking means includes a spring-actuated snap-over control leveioperatively connected with said locking dog claim 11, wherein the inside operated retracting means includes a link having a lost motion operating connection with the roll-back and having a cam-shaped portion thereon forfengagement with the projection on the locking dog to move the same to blocking position and spring pressure operated means for automatically returning the link to a neutral position when it is operated to move the dog to blocking position.

14. Ina latch mechanism for a door of a vehicle body, the wr'nbination of a latch bolt. a

roll-back therefor. an outside operated retracting means operatively associated with said roll-back. a locking dog movable to a. position blocking said outside retracting means, an inside operated retracting means operatively connected with said roll-back, said locking dog having a projection operable by said inside operated retracting means for movement oi the locking dog to blocking position, and locking means operable with a key from the outside of the door to set said looking dog in blocking position or to move said looking dog to retracted position after it has been moved to blocking position by the inside operated retracting means, 1

15. A door latch mechanism as set forth in claim 14, wherein the key-operated locking means includes a spring-actuated snap-over control lever operatively connected with said looking dog and arranged to snap over a dead-center when moved from one extreme position to the other, the key-operated locking means including an element rotatable with the key and having a lost motion operating connection with said snapover control lever.

16. A door latch mechanism as set forth in claim 14, wherein the inside operated retracting means includes a link having a lost motion operating connection with the roll-back and having a cam-shaped portion thereon for engagement with the projection on the locking dog to move the same in blocking position and spring pressure operated means for automatically returning the link to a neutral position when it is operated to move the dog to blocking position.

17. A latch mechanism as set forth in claim 2, including inside operated retracting means adapted to actuate the locking dog to blocking position, the said means including spring pressure operated means for automatically returning the same to a middle neutral position when moved to set the dog in blocking position, whereby correspondingly to reduce the mass that has to be moved by the key of the locking means in returning the dog to retracted position.

18. Latch mechanism for a door of a vehicle body as set forth in claim 2, wherein said locking dog has a projection which is disposed in the path of retracting movement ofthe latchbolt element when said locking dog is in locked position, whereby said latch bolt element moves said dog out of blocking position whenthe door is slammed, the mechanism including inside operated retracting means operatively associated with said roll-back and locking dog so as to set said locking dog in blocking position when moved in one direction from a neutral position and retract said latch bolt element when moved in the opposite direction from the neutral position, and spring pressure operated means for automatically returning said retracting means to neutral posi- 12 tion to correspondingly reduce inertia to be overcome n movi l the dog from blocking position when the door is slammed.

19. A door latch mechanism as set forth in claim 3. including manually operable means for transmitting movement to said link in either direction from a neutral position, and spring pressure operated means for automatically returning the link to neutral position when operated to move the dog to blocking position, whereby correspondingly to reduce the mass that has to be moved with the dog by the latching element when the door is slammed.

20. A door latch mechanism as set forth in claim 4, including manually operable means ior transmitting movement to said link in either direction from a neutral position, and spring pressure operated means for automatically returning the link to neutral position.

21. A door latch mechanism as set forth in claim 5, wherein the inside operated retracting means includes a link having a lost motion operating connection with the roli-backand having a cam-shaped portion thereon for engagement with the projection on the locking dog to move the same to blocking position when the link is moved in one direction from a neutral position, and spring pressure operated means for automatically returning the link to neutral position, whereby correspondingly to reduce the mass that has to be set in motion in returning the dog to retracted position either when the door is slammed or when the key operable locking means is used.

22. A door latch mechanism as set forth in claim 10, wherein the link is movable in either direction from a neutral position, the mechanism including spring pressure operated means for returning the link to neutral position automatically after a forward movement thereof, whereby to avoid the necessity for moving said link with the key of said locking means in unlocking the door.

WILLIAM J. 'I'IERNEY.

CLETUS L. HARMON.

FRED W. A. VILLEMURE.

REFERENCES CITED The following reierences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,143,965 Van Voorhees Jan. 17, 1939 2,183,672 Devereaux Dec. 19, 1939 1,923,688 Rightmyer Aug. 22, 1933 2,329,232 Van Voorhees Sept. 14, 1943 47,741 Morris May 16, 1865 1,741,258 Utley Dec. 31, 1929 1,794,073 Hammerl Feb. 24, 1931 

